Fabrication of High Strength and Low Thermal Conductivity Graphite/Ceramic Composites by Selective Laser Sintering and Gelcasting

2019 ◽  
Vol 56 (9) ◽  
pp. 091404
Author(s):  
吴海华 Wu Haihua ◽  
孙瑜 Sun Yu ◽  
陈奎 Chen Kui ◽  
李亚峰 Li Yafeng
Keyword(s):  
Thermal Conductivity ◽  
Selective Laser Sintering ◽  
High Strength ◽  
Ceramic Composites ◽  
Laser Sintering ◽  
Low Thermal Conductivity

scholarly journals Fabrication of Natural Flake Graphite/Ceramic Composite Parts with Low Thermal Conductivity and High Strength by Selective Laser Sintering

2020 ◽  
Vol 10 (4) ◽  
pp. 1314
Author(s):  
Haihua Wu ◽  
Kui Chen ◽  
Yafeng Li ◽  
Chaoqun Ren ◽  
Yu Sun ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Ceramic Composite ◽  
Selective Laser Sintering ◽  
High Strength ◽  
Laser Sintering ◽  
Post Processing ◽  
Composite Part ◽  
Low Thermal Conductivity ◽  
Powder Composition

The 3D graphite/ceramic composite prototyping parts directly prepared by selective laser sintering (SLS) were porous, which led to poor strength and low thermal conductivity. In order to obtain low thermal conductivity and high strength, its thermal conductivity and compressive strength were adjusted by changing the mixture powder composition and adding post-processing. The result showed that the addition of silicon powder in the mixture powder could significantly improve the compressive strength and thermal conductivity. The addition of expanded graphite was beneficial to the formation of the closed pores in the matrix, which slightly reduced the compressive strength but significantly reduced the thermal conductivity. The 3D graphite/ceramic composite part showed an order of magnitude improvement in compressive strength (from 1.25 to 13.87 MPa) but relatively small change in thermal conductivity (from 1.40 to 2.12 W·m−1K−1) and density (from 0.53 to 1.13 g·cm−3) by post-processing. Reasonable mixture powder composition and post-processing were determined and realized the possibility of fabricating a 3D graphite/ceramic composite part with low thermal conductivity but high compressive strength. Furthermore, it could be used for the repeated casting of steel castings, and through the comparative analysis of casting defects, the prepared graphite/ceramic composite part was expected to replace water glass sand mold.

Ultra-low thermal conductivity and high strength of aerogels/fibrous ceramic composites

2016 ◽  
Vol 36 (6) ◽  
pp. 1487-1493 ◽  
Author(s):  
Jian He ◽  
Xiaolei Li ◽  
Dong Su ◽  
Huiming Ji ◽  
XiaoJing Wang
Keyword(s):  
Thermal Conductivity ◽  
High Strength ◽  
Ceramic Composites ◽  
Low Thermal Conductivity

Simulation and Characterization of Nanoparticle Thermal Conductivity for a Microscale Selective Laser Sintering System

2021 ◽  
Author(s):  
Joshua Grose ◽  
Obehi G. Dibua ◽  
Dipankar Behera ◽  
Chee S. Foong ◽  
Michael Cullinan
Keyword(s):  
Thermal Conductivity ◽  
Selective Laser Sintering ◽  
Primary Source ◽  
Laser Sintering ◽  
Metal Nanoparticle ◽  
Feature Size ◽  
Cad Models ◽  
Minimum Feature Size ◽  
Geometric Arrangements ◽  
Thermal Simulations

Abstract Additive Manufacturing (AM) technologies are often restricted by the minimum feature size of parts they can repeatably build. The microscale selective laser sintering (μ-SLS) process, which is capable of producing single micron resolution parts, addresses this issue directly. However, the unwanted dissipation of heat within the powder bed of a μ-SLS device during laser sintering is a primary source of error that limits the minimum feature size of the producible parts. A particle scale thermal model is needed to characterize the thermal properties of the nanoparticles undergoing sintering and allow for the prediction of heat affected zones (HAZ) and the improvement of final part quality. Thus, this paper presents a method for the determination of the effective thermal conductivity of metal nanoparticle beds in a microscale selective laser sintering process using finite element simulations in ANSYS. CAD models of nanoparticle groups at various timesteps during sintering are developed from Phase Field Modeling (PFM) output data, and steady state thermal simulations are performed on each group. The complete simulation framework developed in this work is adaptable to particle groups of variable sizes and geometric arrangements. Results from the thermal models are used to estimate the thermal conductivity of the copper nanoparticles as a function of sintering duration.

Preparation of high-strength Si3N4 antenna window using selective laser sintering

2021 ◽  
Author(s):  
Kejie Wang ◽  
Chonggao Bao ◽  
Chengyu Zhang ◽  
Yinghong Li ◽  
Rongzhen Liu ◽  
...  
Keyword(s):  
Selective Laser Sintering ◽  
High Strength ◽  
Laser Sintering

Elephant ivory: A low thermal conductivity, high strength nanocomposite

2006 ◽  
Vol 21 (1) ◽  
pp. 287-292 ◽  
Author(s):  
Michael B. Jakubinek ◽  
Champika J. Samarasekera ◽  
Mary Anne White
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
High Strength ◽  
Mean Free Path ◽  
Boundary Scattering ◽  
Low Thermal Conductivity ◽  
Recent Interest ◽  
Elephant Ivory ◽  
Nanocomposite Structures ◽  
Structure Properties

There has been much recent interest in heat transport in nanostructures, and alsoin the structure, properties, and growth of biological materials. Here we present measurements of thermal properties of a nanostructured biomineral, ivory. The room-temperature thermal conductivity of ivory is anomalously low in comparison with its constituent components. Low-temperature (2–300 K) measurements ofthermal conductivity and heat capacity reveal a glass-like temperature dependenceof the thermal conductivity and phonon mean free path, consistent with increased phonon-boundary scattering associated with nanostructure. These results suggest that biomineral-like nanocomposite structures could be useful in the design of novel high-strength materials for low thermal conductivity applications.

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